RESUMO
The convenience and cost-effectiveness offered by cloud computing have attracted a large customer base. In a cloud environment, the inclusion of the concept of virtualization requires careful management of resource utilization and energy consumption. With a rapidly increasing consumer base of cloud data centers, it faces an overwhelming influx of Virtual Machine (VM) requests. In cloud computing technology, the mapping of these requests onto the actual cloud hardware is known as VM placement which is a significant area of research. The article presents the Dragonfly Algorithm integrated with Modified Best Fit Decreasing (DA-MBFD) is proposed to minimize the overall power consumption and the migration count. DA-MBFD uses MBFD for ranking VMs based on their resource requirement, then uses the Minimization of Migration (MM) algorithm for hotspot detection followed by DA to optimize the replacement of VMs from the overutilized hosts. DA-MBFD is compared with a few of the other existing techniques to show its efficiency. The comparative analysis of DA-MBFD against E-ABC, E-MBFD, and MBFD-MM shows %improvement reflecting a significant reduction in power consumption 8.21 %, 8.6 %, 6.77 %, violations in service level agreement from 9.25 %, 6.98 %-7.86 % and number of migrations 6.65 %, 8.92 %, 7.02 %, respectively.
RESUMO
Six novel red photoluminescent Eu3+ complexes with 3-formyl chromone as the primary sensitizer (L) were synthesized using the solution precipitation method. These complexes are [Eu(L3).X] where X is 2H2O (C1), phen (C2), neo (C3), bipy (C4), dmph (C5), and biquno (C6). These complexes were characterized by elemental analysis, EDAX analysis, SEM, FT-IR, thermo-gravimetric analysis (TGA/DTA) and photoluminescence spectra. The transition rates, quantum efficiency, and J-O intensity parameters were calculated using emission data and luminescence decay time (τ). Complexes exhibit a strong emission peak (5D0 â 7F2) of the Eu3+ ion in their luminescence emission spectra in solid and solution states, making them an effective emitter of the red color in OLEDs. The branching ratio of these complexes ranges from 80.67-82.92 in solid and 50.53-62.65 in solution state; CIE color coordinate of complexes falls in the red region. The color purity ranges [CP(%)] values for solid 95.26-97.27% and for solution ranges 85.11-93.43%. Correlated color temperature (CCT) of the complexes (C1-C6) ranged from 2710 to 3049 K in the solid state and 1775 to 2450 K in the solution state. These complexes are promising red emitters in OLEDs, semiconductors, and leasing devices.
RESUMO
In this work, six reddish orange Sm3+ complexes were synthesized using organic ligand (L) and secondary ligands having hetero atoms by a one-step significant liquid-assisted grinding method and were characterized by spectroscopic techniques. The Urbach energy and band gap energy of the complexes were inspected by a linear fit. Using a least square fitting method, the Judd-Ofelt parameter and radiative properties were also determined. Thermal analysis, colorimetric analysis, luminescence decay time and anti-microbial properties of complexes were studied. The luminescence emission spectra of binary and ternary complexes displayed three characteristic peaks at 565, 603 and 650 nm in the powder form and four peaks at 563, 605, 646 and 703 nm in a solution phase due to 4G5/2 â 6H5/2, 4G5/2 â 6H7/2, 4G5/2 â 6H9/2 and 4G5/2 â 6H11/2 transitions respectively. The most intense transition in the solid phase (4G5/2 â 6H7/2) is accountable for orange color, and in the solution form, the highly luminescent peak (4G5/2 â 6H9/2) is responsible for reddish orange color of Sm3+ complexes. PXRD and SEM analyses suggested that the complexes possess a nanoparticle grain size with crystalline nature. The decent optoelectrical properties of title complexes in the orangish-red visible domain indicated possible applications in the manufacturing of display and optoelectronic devices.
